https://www.gmt400.com/threads/99-l2...d.54517/page-2

Grinding the swirl pads should be straight forward but time consuming on iron. Sounds like the stock intake would hold you back a lot.

Could be a 500-600hp setup depending on the cam.

https://cimg2.ibsrv.net/gimg/www.off...dd333ba854.png

I concur. 9:1 is enough to get away with 93 octane imho on an iron head on a hot July day and 234/240 .651/.640 on a 113 lsa would likely be safe enough with wet exhaust. We did that camshaft on a 468 with 9:1 with a performer rpm air gap and a pro systems 850 and hit 570.1 hp. I’d think the intake would certainly be a restriction and heads as well without port work. I *may* try and experiment with some efi porting and l29 head work if I get bored. I concur with above on .500 and .600 lift. The head setup on these however is a bit complicated with the rotation eliminators being a hair too thick.

L29 head Gen VI BBCs are a great package.

Going 2.19" int valve with the steep shrouding walls of the chamber is restrictive. Grinding away to unshrowd reduced compression.

Some grinding on the quench deck to chamber corner on the exhaust side is beneficial to assist evacuarion pumping loss.

2.07 valves are large enough to support a lot of HP at marine rpm (up to 6000 area).

Peanut Port heads are pretty good. Easy to make power. Perfect for marine. It's all about setup.

The stock cranks are good for more than 5000, but it's how you treat it and prepare it.

L21 engines have forged cranks and pistons. They're rare.

Id really love to hear how a guy goes about using "HP TUNERS" to tune a mefi3 ecm.

Totally caught the typo. Was typing that quickly and meant mefi burn. Amended.